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Introduction
 | Used for: |
- Client-based applications, similar to JavaScript in terms of operation. Only runs in Microsoft Internet Explorer.
- Server-based applications, typically in conjunction with tools such as ASP (Active Server Pages) and ADO (ActiveX Data Objects.
| Also called the Microsoft Visual Basic Scripting Edition, a subset of the Microsoft Visual Basic programming language |
| It is a fast, portable, lightweight interpreter for use in Web browsers and other applications that use Microsoft ActiveX Controls. |
Language Fundamentals
Much of VBScript is based on Visual Basic with minor exceptions based on the specifics of various environments (e.g., web browsers).
Data Types
| VBScript has only one data type called a Variant. | ||||||||
| It is a a special kind of data type that can contain different kinds of information, depending on how it is used. | ||||||||
| Because the Variant is the only data type in VBScript, it is also the data type returned by all functions in VBScript. | ||||||||
| It can contain either numeric or string information. | ||||||||
| It behaves as a number when you use it in a numeric context and as a string when you use it in a string context. | ||||||||
| The Dim statement is used to declare variables. | ||||||||
| Variable names follow the standard rules for naming anything in VBScript.
A variable name:
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Operators
Arithmetic
Exponentiation ^
Unary negation -
Multiplication *
Division /
Integer division \
Modulus arithmetic Mod
Addition +
Subtraction -
String concatenation &
Comparison
Equality =
Inequality <>
Less than <
Greater than >
Less than or equal to <=
Greater than or equal to >=
Object equivalence Is
Logical
Logical negation Not
Logical conjunction And
Logical disjunction Or
Logical exclusion Xor
Logical equivalence Eqv
Logical implication Imp
Control Statements
Essentially VBScript uses the same control statements as Visual Basic
| If...Then...Else |
| Do...Loop |
| For...Next |
| For Each...Next |
| Select Case |
| While...Wend |
| With |
Program Features
| Category | Keywords |
|---|---|
| Array handling | Array Dim, Private, Public, ReDim IsArray Erase LBound, UBound |
| Constants/Literals | Empty Nothing Null True, False |
| Conversions | Abs Asc, AscB, AscW Chr, ChrB, ChrW CBool, CByte CCur, CDate CDbl, CInt CLng, CSng, CStr DateSerial, DateValue Hex, Oct Fix, Int Sgn TimeSerial, TimeValue |
| Dates/Times | Date, Time DateAdd, DateDiff, DatePart DateSerial, DateValue Day, Month, MonthName Weekday, WeekdayName, Year Hour, Minute, Second Now TimeSerial, TimeValue |
| Declarations | Class Const Dim, Private, Public, ReDim Function, Sub Property Get, Property Let, Property Set |
| Error Handling | On Error Err |
| Expressions | Eval Execute RegExp Replace Test |
| Formatting Strings | FormatCurrency FormatDateTime FormatNumber FormatPercent |
| Input/Output | InputBox LoadPicture MsgBox |
| Literals | Empty False Nothing Null True |
| Math | Atn, Cos, Sin, Tan Exp, Log, Sqr Randomize, Rnd |
| Miscellaneous | Eval Function Execute Statement RGB Function |
| Objects | CreateObject Err Object GetObject RegExp |
| Options | Option Explicit |
| Procedures | Call Function, Sub Property Get, Property Let, Property Set |
| Script Engine ID | ScriptEngine ScriptEngineBuildVersion ScriptEngineMajorVersion ScriptEngineMinorVersion |
| Strings | Asc, AscB, AscW Chr, ChrB, ChrW Filter, InStr, InStrB InStrRev Join Len, LenB LCase, UCase Left, LeftB Mid, MidB Right, RightB Replace Space Split StrComp String StrReverse LTrim, RTrim, Trim |
| Variants | IsArray IsDate IsEmpty IsNull IsNumeric IsObject TypeName VarType |
Input/Output
| VBScript, within the web browser environment, is dependent upon the browser (via HTML) for user input/output. |
| VBScript, within the server environment, has input/output access via Active Server Pages (ASP) objects, i.e., Response and Request objects. |
| File I/O is restricted in web browsers due to security considerations. However, file access can be accomplished via system file objects (web server only). |
| VBScript does not have database access capability in the browser; it has access to databases via ASP and related database object technologies (i.e., ActiveX Data Objects, ADO). |
Resources
| http://msdn.microsoft.com/scripting/default.htm |
| http://devguru.com - DevGuru is a very good resource. |